<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
.root{
    position: relative;
}
.root div{
    height: 100px;
    position: absolute;
}
.left,.right{
    width: 300px;
    background-color: yellow;
}
.left{
    left: 0;
}
.right{
    right: 0;
}
.center{
    left: 300px;
    right: 300px;
    background-color: rebeccapurple;
}
    </style>
</head>
<body>
    <div class="root">
        <div class="left">left</div>
        <div class="center">center Lorem ipsum dolor sit amet consectetur adipisicing elit. Sequi voluptatum id possimus repellendus, a laborum asperiores voluptatem voluptas qui ipsa! Aperiam, nisi aliquam? Recusandae sapiente exercitationem, fugit error iste cupiditate.</div>
        <div class="right">right</div>
    </div>
</body>
</html>